Must-have feature Rated 5 out of 5 stars

This is a must-have add-on for anyone who often browses though various text files (source-code, TeX, etc) or mis-configured webservers.
It really should be built in to Firefox.
Agree it would be nice to see some integration with the Options/Applications page, so that the choice could be made permanent.

This review is for a previous version of the add-on (1.7).